fix: leetcode-cn can not use GitHub log in bug (leetcode-tools#46)

Author: yihong0618

lib/plugins/leetcode.js

@@ -540,10 +540,16 @@ plugin.login = function(user, cb) {
 };
 
 function parseCookie(cookie, body, cb) {
+  const isCN = config.app === 'leetcode.cn';
   const SessionPattern = /LEETCODE_SESSION=(.+?)(;|$)/;
-  const csrfPattern = /csrftoken=(.+?)(;|$)/;
+  let csrfPattern;
+  if (isCN) {
+    csrfPattern = /name="csrfmiddlewaretoken" value="(.*?)"/;
+  } else {
+    csrfPattern = /csrftoken=(.+?)(;|$)/;
+  }
+  const reCsrfResult = csrfPattern.exec(isCN? body: cookie);
   const reSessionResult = SessionPattern.exec(cookie);
-  const reCsrfResult = csrfPattern.exec(cookie);
   if (reSessionResult === null || reCsrfResult === null) {
     return cb('invalid cookie?');
   }